Beyond Skin Deep: Phospholipid-Based Nanovesicles as Game-Changers in Transdermal Drug Delivery.

Transdermal administration techniques have gained popularity due to their advantages over oral and parenteral methods. Noninvasive, self-administered delivery devices improve patient compliance and control drug release. Transdermal delivery devices struggle with the skin's barrier function. Molecules over 500 Dalton (Da) and ionized compounds don't permeate through the skin. Drug encapsulation in phospholipid-based vesicular systems is the most effective skin delivery technique. Vesicular carriers include bi-layered liposomes, ultra-deformable liposomes, ethanolic liposomes, transethosomes, and invasomes. These technologies enhance skin drug permeation by increasing formula solubilization, partitioning into the skin, and fluidizing the lipid barrier. Phospholipid-based delivery systems are safe and efficient, making them a promising pharmaceutical and cosmeceutical drug delivery technique. Still, making delivery systems requires knowledge about the physicochemical properties of the drug and carrier, manufacturing and process variables, skin delivery mechanisms, technological advances, constraints, and regulatory requirements. Consequently, this review covers recent research achievements addressing the mentioned concerns.

Effect of chitosan and curcumin nanoparticles against skeletal muscle fibrosis at early regenerative stage of glycerol-injured rat muscles.

INTRODUCTION: Chitosan and curcumin are natural products that have a wide range of beneficial effects including wound healing. However, their high molecular weight and poor water solubility limit their applications. AIMS: Therefore, the current study aims to evaluate the effects of chitosan (Cs) and curcumin (Cn) nanoparticles (NPs) on fibrosis and regeneration of glycerol-injured muscle. METHODS: Muscle injury was induced by intramuscular injection of glycerol into the tibialis anterior muscle of rats. Cs-NPs and Cn-NPs were administered at different doses intraperitoneally after injury. Injured muscles were collected at day 7 after injury, and muscle fibrosis and regeneration were assessed. RESULTS: The present results revealed that Cs-NPs and Cn-NPs treatment significantly decreased fibrosis index and increased the average myotube diameter with shifting of the distribution of myotube diameters towards larger diameters in a dose-dependent manner. Immunohistochemical analysis revealed that Cs-NPs and Cn-NPs treatment significantly decreased the number of CD-68+ cells and Col-1+ area. Results showed that Cn-NPs had a higher protective effect, in the form of attenuating muscle fibrosis and inflammation, and enhancing muscle regeneration, than that of Cs-NPs. CONCLUSIONS: To our knowledge, this is the first study to document the effects of Cs-NPs in injured muscles. The results of study might be a novel approach to attenuate muscle fibrosis in humans using curcumin and chitosan nanoparticles.

Mucoadhesive thermoreversible formulation of metoclopramide for rectal administration: a promising strategy for potential management of chemotherapy-induced nausea and vomiting.

The study aimed to investigate the feasibility of incorporation of metoclopramide hydrochloride (MCP HCl) in mucoadhesive thermoreversible liquid suppository (MCP HCl-LS) to bypass the first-pass metabolism and maximize its efficacy to be a promising substitute for parenteral therapy. MCP HCl-LS was formulated using Pluronic (PF127/PF68) and hydroxypropylmethylcellulose (HPMC) and in vitro evaluated through their gelation temperature, gel strength (GS), mucoadhesive force, and in vitro release studies. Also, the MCP HCl-LS was evaluated for its rheological behavior and examined for rectal mucosal integrity after administration. The results revealed that the MCP HCl-LS; composed of PF127/PF68/HPMC (20/7/0.5% w/w) was in the liquid state at room temperature, experienced gelation at 30.23 °C, with suitable GS of 28.66 s and rectal retention force of 43.03 × 102 dyne/cm2. The pharmacokinetic data showed that the MCP HCl-LS exhibited a significant increase (p < 0.05) in AUC0-480 (219.688 vs 172.333 ng.h.mL-1 of the marketed) and 1.3-fold increase in relative bioavailability compared to Primperan® suppository, indicating that LS formula bypassed the first-pass metabolism. Moreover, MCP HCl-LS did not cause any morphological harm to the rectal tissues suggested that the developed formulation was safe and could be a potentially useful alternative drug carrier for rectal delivery of MCP HCl in patients experiencing chemotherapy-induced nausea and vomiting.

Tolmetin sodium-loaded thermosensitive mucoadhesive liquid suppositories for rectal delivery; strategy to overcome oral delivery drawbacks.

Tolmetin sodium (TS) is a nonsteroidal anti-inflammatory drug (NSAID) indicated for treatment of musculoskeletal issues. As other NSAID, TS displays a marked side effects on the gastro-intestinal (GI) tract after oral administration. Traditional solid suppositories can cause pain and discomfort for patients, may reach the end of the colon; consequently, the drug can undergo the first-pass effect. TS liquid suppository (TS-LS) was developed to enhance patient compliance and rectal mucosal safety in high-risk patients receiving highly NSAID therapy. This work was conducted to optimize and evaluate Poloxamer P407/P188-based thermoresponsive TS-LS by using mucoadhesive polymers such as methylcellulose (MC). TS-LS was prepared by cold method and characterized their in vitro physicochemical properties as gelation temperature (GT), gel strength, bioadhesive properties, and in vitro release. The safety of the prepared suppository on rectum, stomach, and liver was evaluated histologically. Pharmacokinetic analyses were performed to compare rectal TS-LS to orally Rhumtol® capsules. The results showed that the optimized TS-LS; composed of P407/P188/MC (21/9/0.5% w/w) displayed gelation at rectum temperature ∼32.90 °C, gel strength of 21.35 s and rectal retention force at the administration site of 24.25 × 102 dyne/cm2. Moreover, TS-LS did not cause any morphological damage to the rectal tissues. Pharmacokinetic parameters of optimized TS-LS formulation revealed 4.6 fold increase in bioavailability as compared to Rhumtol® capsules. Taken together, the results demonstrated that liquid suppository is a potential and physically safe rectal delivery carrier for improvement rectal bioavailability and in vivo safety of TS.

A pH-sensitive silica nanoparticles for colon-specific delivery and controlled release of catechin: Optimization of loading efficiency and in vitro release kinetics.

Catechin is a naturally occurring flavonoid of the flavan-3-ol subclass with numerous biological functions; however, these benefits are diminished due to several factors, including low water solubility and degradation in the stomach's harsh environment. So, this study aimed to develop an intelligent catechin colon-targeting delivery system with a high loading capacity. This was done by coating surface-decorated mesoporous silica nanoparticles with a pH-responsive enteric polymer called Eudragit®-S100. The pristine wormlike mesoporous silica nanoparticles (< 100 nm) with high surface area and large total pore volume were effectively synthesized and modified with the NH2 group using the post-grafting strategy. Various parameters, including solvent polarity, catechin-carrier mass ratio, and adsorption time, were studied to improve the loading of catechin into the aminated silica nanoparticles. Next, the negatively charged Eudragit®-S100 was electrostatically coated onto the positively charged aminated nanocarriers to shield the loaded catechin from the acidic environment of the stomach (pH 1.9) and to facilitate site-specific delivery in the acidic environment of the colon (pH 7.4). The prepared nanomaterials were evaluated using several methods, including The Brauner-Emmett-Teller, surface area analyzer, zeta sizer, Field Emission Scanning Electron Microscope, Powder X-Ray Diffraction, Fourier Transform Infrared Spectroscopy, Energy-Dispersive X-ray Spectroscopy, and Differential Scanning Calorimetry. In vitro dissolution studies revealed that Eudragit®-S100-coated aminated nanomaterials prevented the burst release of the loaded catechin in the acidic environment, with approximately 90% of the catechin only being released at colonic pH (pH > 7) with a supercase II transport mechanism. As a result, silica nanoparticles coated with Eudragit®-S100 would provide an innovative and promising approach in targeted nanomedicine for the oral delivery of catechin and related medicines for treating diseases related to the colon, such as colorectal cancer and irritable bowel syndrome.

Formulation, and optimization of transdermal Atorvastatin Calcium-Loaded Ultra-flexible vesicles; ameliorates poloxamer 407-caused dyslipidemia.

Atorvastatin calcium (AC), a cholesterol-lowering medication, has limited oral bioavailability (14 %) and adverse impacts on the gastrointestinal tract (GIT), liver, and muscle. So, in an effort to improve the poor availability and overcome the hepatotoxicity complications attendant to peroral AC administration, transdermal transfersomal gel (AC-TFG) was developed as a convenient alternative delivery technique. The impact of utilizing an edge activator (EA) and varying the phosphatidylcholine (PC): EA molar ratio on the physico-chemical characteristics of the vesicles was optimized through a Quality by Design (QbD) strategy. The optimal transdermal AC-TFG was tested in an ex-vivo permeation study employing full-thickness rat skin, Franz cell experiments, an in-vivo pharmacokinetics and pharmacodynamics (PK/PD) evaluation, and a comparison to oral AC using poloxamer-induced dyslipidemic Wister rats. The optimized AC-loaded TF nanovesicles predicted by the 23-factorial design strategy had a good correlation with the measured vesicle diameter of 71.72 ± 1.159 nm, encapsulation efficiency of 89.13 ± 0.125 %, and cumulative drug release of 88.92 ± 3.78 % over 24 h. Ex-vivo data revealed that AC-TF outperformed a free drug in terms of permeation. The pharmacokinetic parameters of optimized AC-TFG demonstrated 2.5- and 13.3-fold significant improvements in bioavailability in comparison to oral AC suspension (AC-OS) and traditional gel (AC-TG), respectively. The transdermal vesicular technique preserved the antihyperlipidemic activity of AC-OS without increasing hepatic markers. Such enhancement was proven histologically by preventing the hepatocellular harm inflicted by statins. The results showed that the transdermal vesicular system is a safe alternative way to treat dyslipidemia with AC, especially when given over a long period of time.

Formulation and optimization of theophylline-loaded enteric-coated spanlastic nanovesicles for colon delivery; Ameliorate acetic acid-induced ulcerative colitis.

Treatment of colon diseases presents one of the most significant obstacles to drug delivery due to the inability to deliver sufficient drug concentration selectively to the colon. The goal of the proposed study was to develop, optimize, and assess an effective colon target delivery system of theophylline-based nanovesicles (TP-NVs) surrounded by a biodegradable polymeric shell of chitosan (CS) and Eudragit L100 (EL100) for the treatment of ulcerative colitis (UC). TP-loaded nanovesicles were fabricated using the ethanol injection method and coated with CS and EL100, respectively. We used a 32-factorial design approach to optimize the concentration of CS and EL100 to minimize particle size (PS) and maximize the cumulative amount of theophylline released (CTR) after 24 h. The optimized formulation was described using transmission electron microscopy (TEM), differential scanning calorimetry (DSC), and in vitro release. In-vivo quantification of theophylline in the gastrointestinal tract and in-vivo targeting potential in a rat model of acetic acid-induced colitis were also thoroughly evaluated. The characteristics of the optimal formula predicted by the 32-factorial design approach corresponded exceptionally well with the measured PS of 271.3 nm, the zeta potential of -39.9 mV, and CTR of 3.95, and a 99.93% after 5 and 24 h, respectively. Notably, the in vivo results in the rat model of colitis showed that the formulation with an optimized coat significantly improved theophylline distribution to the colon and markedly decreased the expression of interleukin-6 and ulcerative lesions compared to a pure theophylline solution. These outcomes elucidated the feasibility of a 32-factorial design to detect the crucial interactions between the study's components. Our findings suggested that enteric-coated nanovesicles formulations with optimal coat compositions of 0.2693% (w/v) and 0.75% (w/v) of CS and EL100, respectively, were promising carriers for colonic delivery of theophylline, a rate-limiting step in the treatment of UC.

Synthesis and Evaluation of High Functionality and Quality Cell-penetrating Peptide Conjugated Lipid for Octaarginine Modified PEGylated Liposomes In U251 and U87 Glioma Cells.

The use of peptide ligand modified PEGylated liposomes has been widely investigated for tumor targeting. Peptides are mainly inserted in the liposomal lipid bilayer using PEG2K-lipid spacer (Peptide-PEG2K-DSPE). However, a lower cellular uptake from longer nonlinear PEG2K spacer was reported, we here synthesized a high functionality and quality (HFQ) lipid with a short, linear serine-glycine repeated peptide [(SG)5] spacer. The objective of the current study is to develop novel octaarginine (R8) peptide-HFQ lipid grafted PEGylated liposomes for glioma cells targeting. In vitro liposomes characterization showed that the mean particle size of all liposomal formulations was in the nano-scale range < 120 nm, with a small PDI value (i.e. ∼0.2) and had a spherical shape under Transmission Electron Microscope, indicating a homogenous particle size distribution. The flow cytometry in vitro cellular association data with U251 MG and U87 cells revealed that 1.5% R8-(SG)5-lipid-PEGylated liposomes exhibited significantly higher cellular association of ∼15.87 and 7.59-fold than the conventional R8-PEG2K-lipid-PEGylated liposomes (10.4 and 6.19-fold), respectively, relative to the unmodified PEGylated liposomes. Moreover, intracellular distribution studies using confocal laser scanning microscopy (CLSM) corroborated the results of the in vitro cell association. The use of ligand-HFQ-lipid liposomes could be a potential alternative to ligand-PEG2K-lipid-modified liposomes as a drug delivery system for tumor targeting.

Brain uptake and accumulation of new levofloxacin-doxycycline combination through the use of solid lipid nanoparticles: Formulation; Optimization and in-vivo evaluation.

The objective of this study is to investigate the feasibility of delivery of novel levofloxacin/ doxycycline (LEVO/DOX) combination to the brain by intranasal route to achieve a significant local concentration in the brain and a direct nose-to-brain pathway. Solid lipid nanoparticles (SLN) were selected as a drug carrier and employed Box-Behnken design for optimizing LEVO/DOX-SLN to achieve minimum particle size and maximum apparent entrapment efficiency (EE). SLNs were prepared by hot emulsification and characterized. In vitro release of optimized formulations showed prolonged drug release from the optimized formulation. The results of pharmacokinetic study of the optimized SLN-HPMC gel in plasma and brain revealed significant increase in the brain peak concentration (420, 315 ng/g), the AUC 0-360 min (57130 and 48693.13 ng. min/g) in comparison to intranasal LEVO/DOX free solution with the values of (160, 120) ng/g, (36850, 27637.5 ng⋅min/g) for LEVO and DOX, respectively. The optimized LD-SLN-HPMC gel gave a drug-targeting efficiency (DTE %) of 149.815 and 161.969 for LEVO and DOX, respectively, in comparison to the intravenous route. Moreover, the optimized formulation had a direct transport percentage (DTP %) of 33.285 and 40.236 for LEVO and DOX, respectively, which indicates a significant contribution of direct nose-to-brain pathway in brain drug delivery.

Impact of nanostructured lipid carriers on dapsone delivery to the skin: in vitro and in vivo studies.

The main objective of this study was to develop, characterize and evaluate the potential use of dapsone-loaded nanostructured lipid carriers (NLCs) as a topical treatment for acne. Differently charged NLC formulations were successfully prepared using an emulsification/sonication method. The particle sizes ranged from 106.2 ±â€¯5.6 nm to 151.3 ±â€¯7.4 nm, and the NLCs possessed the predicted surface charges, depending on the emulsifier used (Tween 80, Transcutol P, or cetyltrimethylammonium bromide). The entrapment efficiencies ranged from 76.5 ±â€¯3.8% to 91.1 ±â€¯3.9%. Selected formulations were assessed for possible interactions, in vitro release, ex vivo skin permeation, pharmacological efficacy and safety compared with a hydroalcoholic solution. Dapsone was embedded in the lipid matrix of NLCs and behaved as controlled release system with a good occlusive effect. Dapsone-loaded cationic NLC formulation enhanced the skin permeation of dapsone, increase the amount of dapsone retained in the skin in controlled manner, and improved the anti-rosacea activity. Based on these encouraging results, cationic NLC represents a promising carrier for the safe topical delivery of dapsone.

Real-Time Label-Free Targeting Assessment and in Vitro Characterization of Curcumin-Loaded Poly-lactic-co-glycolic Acid Nanoparticles for Oral Colon Targeting.

The exploitation of curcumin for oral disease treatment is limited by its low solubility, poor bioavailability, and low stability. Surface-functionalized poly-lactic-co-glycolic acid (PLGA) nanoparticles (NPs) have shown promising results to ameliorate selective delivery of drugs to the gastro-intestinal tract. In this study, curcumin-loaded PLGA NPs (C-PLGA NPs) of about 200 nm were surface-coated with chitosan (CS) for gastro-intestinal mucosa adhesion, wheat germ agglutinin (WGA) for colon targeting or GE11 peptide for tumor colon targeting. Spectrometric and zeta potential analyses confirmed the successful functionalization of the C-PLGA NPs. Real-time label-free assessment of the cell membrane-NP interactions and NP cell uptake were performed by quartz crystal microbalance coupled with supported lipid bilayers and by surface plasmon resonance coupled with living cells. The study showed that CS-coated C-PLGA NPs interact with cells by the electrostatic mechanism, while both WGA- and GE11-coated C-PLGA NPs interact and are taken up by cells by specific active mechanisms. In vitro cell uptake studies corroborated the real-time label-free assessment by yielding a curcumin cell uptake of 7.3 ± 0.3, 13.5 ± 1.0, 27.3 ± 4.9, and 26.0 ± 1.3 µg per 104 HT-29 cells for noncoated, CS-, WGA-, and GE11-coated C-PLGA NPs, respectively. Finally, preliminary in vivo studies showed that the WGA-coated C-PLGA NPs efficiently accumulate in the colon after oral administration to healthy Balb/c mice. In summary, the WGA- and GE11-coated C-PLGA NPs displayed high potential for application as active targeted carriers for anticancer drug delivery to the colon.